This data set contains polygons representing the approximate areas used in the orthophoto product for each capture date. The NHAP photographs were acquired at 40,000 feet above mean terrain with flight lines centered on the 1:24,000-scale USGS map series. The orthophoto data set was received with a quadrangle boundaries shapefile, attributed with capture date for each quadrangle. The quadrangle boundaries were converted to a feature class and dissolved on the capture date field. The capture date areas are only approximate, however, due to the variable placement of seamlines during processing to create a continuous statewide image.